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a27bc11f4b
Switch to using the asm-generic/uaccess functions for non-MMU builds.
Remove all the m68knommu local specific uaccess defines and macros.
There is nothing so special about the m68knommu targets that they cannot
use all of the asm-generic uaccess support. Using the asm-generic
uaccess definitions also resolves some of the existing problems with
missing __user annotations in the m68knommu specific functions.
The elimination of all of the contents of uaccess_no.h means we can fold
the uaccess_mm.h back into uaccess.h - and just have the single file
now.
The resulting generated code ends up being slightly smaller (by a few
hundred bytes) due to the compilers ability to better optimize load
and stores without forcing its hand with asm statements.
Specifically trivial cases like this contrived example:
get_user(x, ptr);
x++;
put_user(x, ptr);
end up now being optimized to a single instruction on m68k. More
generally the compiler can avoid using a temporary register in many
cases as well.
Reported-by: kernel test robot <lkp@intel.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>
397 lines
10 KiB
C
397 lines
10 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef __M68K_UACCESS_H
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#define __M68K_UACCESS_H
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#ifdef CONFIG_MMU
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/*
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* User space memory access functions
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*/
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#include <linux/compiler.h>
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#include <linux/types.h>
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#include <asm/segment.h>
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#include <asm/extable.h>
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/* We let the MMU do all checking */
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static inline int access_ok(const void __user *addr,
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unsigned long size)
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{
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return 1;
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}
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/*
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* Not all varients of the 68k family support the notion of address spaces.
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* The traditional 680x0 parts do, and they use the sfc/dfc registers and
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* the "moves" instruction to access user space from kernel space. Other
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* family members like ColdFire don't support this, and only have a single
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* address space, and use the usual "move" instruction for user space access.
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*
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* Outside of this difference the user space access functions are the same.
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* So lets keep the code simple and just define in what we need to use.
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*/
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#ifdef CONFIG_CPU_HAS_ADDRESS_SPACES
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#define MOVES "moves"
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#else
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#define MOVES "move"
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#endif
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extern int __put_user_bad(void);
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extern int __get_user_bad(void);
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#define __put_user_asm(res, x, ptr, bwl, reg, err) \
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asm volatile ("\n" \
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"1: "MOVES"."#bwl" %2,%1\n" \
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"2:\n" \
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" .section .fixup,\"ax\"\n" \
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" .even\n" \
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"10: moveq.l %3,%0\n" \
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" jra 2b\n" \
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" .previous\n" \
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"\n" \
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" .section __ex_table,\"a\"\n" \
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" .align 4\n" \
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" .long 1b,10b\n" \
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" .long 2b,10b\n" \
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" .previous" \
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: "+d" (res), "=m" (*(ptr)) \
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: #reg (x), "i" (err))
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/*
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* These are the main single-value transfer routines. They automatically
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* use the right size if we just have the right pointer type.
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*/
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#define __put_user(x, ptr) \
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({ \
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typeof(*(ptr)) __pu_val = (x); \
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int __pu_err = 0; \
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__chk_user_ptr(ptr); \
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switch (sizeof (*(ptr))) { \
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case 1: \
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__put_user_asm(__pu_err, __pu_val, ptr, b, d, -EFAULT); \
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break; \
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case 2: \
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__put_user_asm(__pu_err, __pu_val, ptr, w, r, -EFAULT); \
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break; \
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case 4: \
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__put_user_asm(__pu_err, __pu_val, ptr, l, r, -EFAULT); \
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break; \
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case 8: \
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{ \
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const void __user *__pu_ptr = (ptr); \
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asm volatile ("\n" \
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"1: "MOVES".l %2,(%1)+\n" \
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"2: "MOVES".l %R2,(%1)\n" \
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"3:\n" \
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" .section .fixup,\"ax\"\n" \
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" .even\n" \
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"10: movel %3,%0\n" \
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" jra 3b\n" \
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" .previous\n" \
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"\n" \
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" .section __ex_table,\"a\"\n" \
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" .align 4\n" \
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" .long 1b,10b\n" \
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" .long 2b,10b\n" \
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" .long 3b,10b\n" \
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" .previous" \
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: "+d" (__pu_err), "+a" (__pu_ptr) \
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: "r" (__pu_val), "i" (-EFAULT) \
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: "memory"); \
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break; \
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} \
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default: \
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__pu_err = __put_user_bad(); \
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break; \
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} \
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__pu_err; \
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})
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#define put_user(x, ptr) __put_user(x, ptr)
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#define __get_user_asm(res, x, ptr, type, bwl, reg, err) ({ \
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type __gu_val; \
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asm volatile ("\n" \
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"1: "MOVES"."#bwl" %2,%1\n" \
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"2:\n" \
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" .section .fixup,\"ax\"\n" \
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" .even\n" \
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"10: move.l %3,%0\n" \
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" sub.l %1,%1\n" \
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" jra 2b\n" \
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" .previous\n" \
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"\n" \
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" .section __ex_table,\"a\"\n" \
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" .align 4\n" \
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" .long 1b,10b\n" \
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" .previous" \
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: "+d" (res), "=&" #reg (__gu_val) \
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: "m" (*(ptr)), "i" (err)); \
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(x) = (__force typeof(*(ptr)))(__force unsigned long)__gu_val; \
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})
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#define __get_user(x, ptr) \
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({ \
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int __gu_err = 0; \
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__chk_user_ptr(ptr); \
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switch (sizeof(*(ptr))) { \
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case 1: \
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__get_user_asm(__gu_err, x, ptr, u8, b, d, -EFAULT); \
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break; \
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case 2: \
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__get_user_asm(__gu_err, x, ptr, u16, w, r, -EFAULT); \
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break; \
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case 4: \
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__get_user_asm(__gu_err, x, ptr, u32, l, r, -EFAULT); \
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break; \
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case 8: { \
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const void __user *__gu_ptr = (ptr); \
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union { \
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u64 l; \
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__typeof__(*(ptr)) t; \
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} __gu_val; \
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asm volatile ("\n" \
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"1: "MOVES".l (%2)+,%1\n" \
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"2: "MOVES".l (%2),%R1\n" \
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"3:\n" \
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" .section .fixup,\"ax\"\n" \
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" .even\n" \
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"10: move.l %3,%0\n" \
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" sub.l %1,%1\n" \
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" sub.l %R1,%R1\n" \
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" jra 3b\n" \
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" .previous\n" \
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"\n" \
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" .section __ex_table,\"a\"\n" \
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" .align 4\n" \
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" .long 1b,10b\n" \
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" .long 2b,10b\n" \
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" .previous" \
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: "+d" (__gu_err), "=&r" (__gu_val.l), \
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"+a" (__gu_ptr) \
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: "i" (-EFAULT) \
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: "memory"); \
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(x) = __gu_val.t; \
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break; \
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} \
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default: \
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__gu_err = __get_user_bad(); \
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break; \
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} \
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__gu_err; \
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})
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#define get_user(x, ptr) __get_user(x, ptr)
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unsigned long __generic_copy_from_user(void *to, const void __user *from, unsigned long n);
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unsigned long __generic_copy_to_user(void __user *to, const void *from, unsigned long n);
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#define __suffix0
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#define __suffix1 b
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#define __suffix2 w
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#define __suffix4 l
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#define ____constant_copy_from_user_asm(res, to, from, tmp, n1, n2, n3, s1, s2, s3)\
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asm volatile ("\n" \
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"1: "MOVES"."#s1" (%2)+,%3\n" \
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" move."#s1" %3,(%1)+\n" \
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" .ifnc \""#s2"\",\"\"\n" \
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"2: "MOVES"."#s2" (%2)+,%3\n" \
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" move."#s2" %3,(%1)+\n" \
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" .ifnc \""#s3"\",\"\"\n" \
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"3: "MOVES"."#s3" (%2)+,%3\n" \
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" move."#s3" %3,(%1)+\n" \
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" .endif\n" \
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" .endif\n" \
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"4:\n" \
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" .section __ex_table,\"a\"\n" \
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" .align 4\n" \
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" .long 1b,10f\n" \
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" .ifnc \""#s2"\",\"\"\n" \
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" .long 2b,20f\n" \
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" .ifnc \""#s3"\",\"\"\n" \
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" .long 3b,30f\n" \
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" .endif\n" \
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" .endif\n" \
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" .previous\n" \
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"\n" \
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" .section .fixup,\"ax\"\n" \
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" .even\n" \
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"10: addq.l #"#n1",%0\n" \
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" .ifnc \""#s2"\",\"\"\n" \
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"20: addq.l #"#n2",%0\n" \
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" .ifnc \""#s3"\",\"\"\n" \
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"30: addq.l #"#n3",%0\n" \
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" .endif\n" \
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" .endif\n" \
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" jra 4b\n" \
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" .previous\n" \
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: "+d" (res), "+&a" (to), "+a" (from), "=&d" (tmp) \
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: : "memory")
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#define ___constant_copy_from_user_asm(res, to, from, tmp, n1, n2, n3, s1, s2, s3)\
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____constant_copy_from_user_asm(res, to, from, tmp, n1, n2, n3, s1, s2, s3)
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#define __constant_copy_from_user_asm(res, to, from, tmp, n1, n2, n3) \
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___constant_copy_from_user_asm(res, to, from, tmp, n1, n2, n3, \
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__suffix##n1, __suffix##n2, __suffix##n3)
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static __always_inline unsigned long
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__constant_copy_from_user(void *to, const void __user *from, unsigned long n)
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{
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unsigned long res = 0, tmp;
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switch (n) {
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case 1:
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__constant_copy_from_user_asm(res, to, from, tmp, 1, 0, 0);
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break;
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case 2:
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__constant_copy_from_user_asm(res, to, from, tmp, 2, 0, 0);
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break;
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case 3:
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__constant_copy_from_user_asm(res, to, from, tmp, 2, 1, 0);
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break;
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case 4:
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__constant_copy_from_user_asm(res, to, from, tmp, 4, 0, 0);
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break;
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case 5:
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__constant_copy_from_user_asm(res, to, from, tmp, 4, 1, 0);
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break;
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case 6:
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__constant_copy_from_user_asm(res, to, from, tmp, 4, 2, 0);
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break;
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case 7:
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__constant_copy_from_user_asm(res, to, from, tmp, 4, 2, 1);
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break;
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case 8:
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__constant_copy_from_user_asm(res, to, from, tmp, 4, 4, 0);
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break;
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case 9:
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__constant_copy_from_user_asm(res, to, from, tmp, 4, 4, 1);
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break;
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case 10:
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__constant_copy_from_user_asm(res, to, from, tmp, 4, 4, 2);
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break;
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case 12:
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__constant_copy_from_user_asm(res, to, from, tmp, 4, 4, 4);
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break;
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default:
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/* we limit the inlined version to 3 moves */
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return __generic_copy_from_user(to, from, n);
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}
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return res;
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}
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#define __constant_copy_to_user_asm(res, to, from, tmp, n, s1, s2, s3) \
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asm volatile ("\n" \
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" move."#s1" (%2)+,%3\n" \
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"11: "MOVES"."#s1" %3,(%1)+\n" \
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"12: move."#s2" (%2)+,%3\n" \
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"21: "MOVES"."#s2" %3,(%1)+\n" \
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"22:\n" \
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" .ifnc \""#s3"\",\"\"\n" \
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" move."#s3" (%2)+,%3\n" \
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"31: "MOVES"."#s3" %3,(%1)+\n" \
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"32:\n" \
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" .endif\n" \
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"4:\n" \
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"\n" \
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" .section __ex_table,\"a\"\n" \
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" .align 4\n" \
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" .long 11b,5f\n" \
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" .long 12b,5f\n" \
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" .long 21b,5f\n" \
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" .long 22b,5f\n" \
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" .ifnc \""#s3"\",\"\"\n" \
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" .long 31b,5f\n" \
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" .long 32b,5f\n" \
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" .endif\n" \
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" .previous\n" \
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"\n" \
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" .section .fixup,\"ax\"\n" \
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" .even\n" \
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"5: moveq.l #"#n",%0\n" \
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" jra 4b\n" \
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" .previous\n" \
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: "+d" (res), "+a" (to), "+a" (from), "=&d" (tmp) \
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: : "memory")
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static __always_inline unsigned long
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__constant_copy_to_user(void __user *to, const void *from, unsigned long n)
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{
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unsigned long res = 0, tmp;
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switch (n) {
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case 1:
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__put_user_asm(res, *(u8 *)from, (u8 __user *)to, b, d, 1);
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break;
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case 2:
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__put_user_asm(res, *(u16 *)from, (u16 __user *)to, w, r, 2);
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break;
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case 3:
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__constant_copy_to_user_asm(res, to, from, tmp, 3, w, b,);
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break;
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case 4:
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__put_user_asm(res, *(u32 *)from, (u32 __user *)to, l, r, 4);
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break;
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case 5:
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__constant_copy_to_user_asm(res, to, from, tmp, 5, l, b,);
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break;
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case 6:
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__constant_copy_to_user_asm(res, to, from, tmp, 6, l, w,);
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break;
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case 7:
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__constant_copy_to_user_asm(res, to, from, tmp, 7, l, w, b);
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break;
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case 8:
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__constant_copy_to_user_asm(res, to, from, tmp, 8, l, l,);
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break;
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case 9:
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__constant_copy_to_user_asm(res, to, from, tmp, 9, l, l, b);
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break;
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case 10:
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__constant_copy_to_user_asm(res, to, from, tmp, 10, l, l, w);
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break;
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case 12:
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__constant_copy_to_user_asm(res, to, from, tmp, 12, l, l, l);
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break;
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default:
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/* limit the inlined version to 3 moves */
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return __generic_copy_to_user(to, from, n);
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}
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return res;
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}
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static inline unsigned long
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raw_copy_from_user(void *to, const void __user *from, unsigned long n)
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{
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if (__builtin_constant_p(n))
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return __constant_copy_from_user(to, from, n);
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return __generic_copy_from_user(to, from, n);
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}
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static inline unsigned long
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raw_copy_to_user(void __user *to, const void *from, unsigned long n)
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{
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if (__builtin_constant_p(n))
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return __constant_copy_to_user(to, from, n);
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return __generic_copy_to_user(to, from, n);
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}
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#define INLINE_COPY_FROM_USER
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#define INLINE_COPY_TO_USER
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#define user_addr_max() \
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(uaccess_kernel() ? ~0UL : TASK_SIZE)
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extern long strncpy_from_user(char *dst, const char __user *src, long count);
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extern __must_check long strnlen_user(const char __user *str, long n);
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unsigned long __clear_user(void __user *to, unsigned long n);
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#define clear_user __clear_user
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#else /* !CONFIG_MMU */
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#include <asm-generic/uaccess.h>
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#endif
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#endif /* _M68K_UACCESS_H */
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